eslint@4.1.1 --init installs eslint@3.19.0

[btmills]

Originally reported on Stack Overflow.

Tell us about your environment

• ESLint Version: 4.1.1
• Node Version: 7.10.0
• npm Version: 4.6.1

What parser (default, Babel-ESLint, etc.) are you using? n/a

Please show your full configuration: n/a

What did you do? Please include the actual source code causing the issue.

~$ mkdir test
~$ cd test
~/test$ echo '{ "private": true }' > package.json
~/test$ npm install --save-dev eslint
# ...
~/test$ node --version
v7.10.0
~/test$ npm --version
4.6.1
~/test$ node_modules/.bin/eslint --version
v4.1.1
~/test$ node_modules/.bin/eslint --init
? How would you like to configure ESLint? Use a popular style guide
? Which style guide do you want to follow? Airbnb
? Do you use React? No
? What format do you want your config file to be in? JavaScript
Checking peerDependencies of eslint-config-airbnb-base
Installing eslint-config-airbnb-base@latest, eslint@^3.19.0, eslint-plugin-import@^2.2.0
# ...
Successfully created .eslintrc.js file in ~/test
~/test$ node_modules/.bin/eslint --version
v3.19.0

What did you expect to happen?

eslint@4.1.1 is still installed.

What actually happened? Please include the actual, raw output from ESLint.

eslint@3.19.0 is installed.

[not-an-aardvark]

I think this is intended and was introduced in #8713. eslint-config-airbnb doesn't support ESLint 4.x, so eslint --init tries to install the right versions to make things work.

[maxlapides]

I am seeing a similar issue. When I install ESLint, I am always getting v3.19.0 of the CLI:

yarn remove eslint
yarn add eslint --dev
./node_modules/.bin/eslint -v
> v3.19.0

[maxlapides]

Okay I figured out that this was happening because one of my dependencies requires eslint 3. It's kind of unexpected that my dependency's required version of eslint would override the version required by the project itself, but perhaps I don't understand the complexities here.

[kaicataldo]

@maxlapides A number of breaking changes were introduced on the plugin authoring side of things in ESLint v4. Installing ESLint v4 with a plugin that has not been updated yet could result in a broken installation, so the behavior you're seeing is intentional to ensure that everything works together.

[nzakas]

This still seems like a bug to me. It might be doing the right thing to make stuff work, but I don't think we should be installing a different version of ESLint during --init. I'd rather see an error message output.

[kaicataldo]

Added back labels while we continue this discussion.

[mysticatea]

OK, in that case, how about we add a question to confirm to install a different version of ESLint?

Preconditions: when package.json has a ESLint version that the chosen config does not support.

  ~/test$ node_modules/.bin/eslint --init
  ? How would you like to configure ESLint? Use a popular style guide
  ? Which style guide do you want to follow? Airbnb
  ? Do you use React? No
+ ? The style guide Airbnb requires eslint@^3.19. Do you install it? Yes
  ? What format do you want your config file to be in? JavaScript
  Checking peerDependencies of eslint-config-airbnb-base
  Installing eslint-config-airbnb-base@latest, eslint@^3.19.0, eslint-plugin-import@^2.2.0
  # ...
  Successfully created .eslintrc.js file in ~/test

[nunofreitasbotelho]

Has anyone tried to upgrade the eslint after the whole config finishes? It would be like this:
Get -v 4.1.0
Asks for Airbnb Config? Y
Downgrades to -v 3.19.0
Upgrade to -v 4.1.0

[nzakas]

@mysticatea I think we need to be more explicit:

The style guide Airbnb requires eslint@3.9.0. You are currently using eslint@4.1.0. Do you want to downgrade?